Musical instrument keyboards



June 7, 1966 A. w. NoRDQUlsT MUSICAL INSTRUMENT KEYBARDS Fiied Jan. 22 195s /nvemor Alber W. Nordquisf am; @LM

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United States Patent O Read & Co., Incorporated, Ivoryton, Conn., a corporation of Connecticut Filed Jan. 22, 1965, Ser. No. 427,409 5 Claims. (Cl. 84-434) This invention relates to musical instrument keyboards and more particularly to an improved balance pin and keyboard assembly.

Musical keyboard instruments often include a plurality of keys in parallel alignment which are pivotal about a point between their ends on a transverselyextending balance rail. Means are provided for holding the keys in a fixed position with respect to the balance rail While permitting the keys to pivot on the balance rail. Such means have often included a metal pin driven into the balance rail and extending upwardly through a slot in the key. Some `type of bushing, such as felt cloth, is then provided in the slo-t between the key and the metal pin to provide quiet operation and the proper touch for the musician playing the instrument.

Such constructions have certain disadvantages. Metal balance pins must be machined to proper size, adding to the cost of manufacture. Occasionally when such metal pins are being driven into the balance rail, the balance rail will split,y necessitating repair or scrapping of the keyboard. Moreover, as mentioned above, a bushing is required in addition to the balance pin, increasing the number and oost of parts as well as increasing the assembly operations required.

It is an object of this invention to provide an improved,y

low cost keyboard assembly for a' musical instrument.

Another object of the invention is to provide-a low cost balance pin, which facilitates manufacture of keyboards for musical instruments.

Stillanother object of the invention is to provide a keyboardassembly wherein the need for bushing the keys about the balance pins is obviated.

A feature of the invention is the provision of a balance pin made of flexible plastic and of unita-ry construction including two elongated cylindrical segments joined by a hinge portion of I-shaped cross section.

Another feature of the invention the provision of a lkeyboard assembly utilizing such a balance pin wherein the hinge portion of the balance pin mates with a groove,

-use in a musical keyboard instrument is provided of flexible plastic. The balance pin is of unitary construction comprised of first and second elongated cylindrical seg- `ments which are axially aligned.` The segments are joined by an integral hinge portion of I-shaped cross section comprising a pair of flanges joined by a web. Each flange is fixed to an end of a respective one of the first and second segments and extends trans-Versally with respect thereto. The web portion joining the two flanges is resilient and iiexible and extends the full length of the flanges to provide a hinged connection therebetween.

3,254,554 Patented June 7, 1966 The balance pin is incorporated in a keyboard assembly for mounting the key .pivotally on a balance rail.

One of the cylindrical segments of the pin is inserted in a hole in the key associated therewith, The other of the cylindrical segments is inserted in a hole in the balance rail. The hole in the balance rail is disposed in the bottom of a longitudinal sl-ot running the length of the balance rail. A portion of the hinge joining the two segments and including one of the flanges mates in the groove in the balance rail to align the pin with respect to the key associated therewith and prevent rotation of the pin with respect to the balance rail.

Referring now more particularly to the drawings, a piano keyboard assembly and a balance pin therefor is shown constructed in accordance with the invention. Although a piano keyboard assembly is shown, other keyboards, such as org-an keyboards, could be constructed in accordance with this invention. The invention is shown in connection with a single key, 'but it is to be understood that a plurality of keys such as the one described are aligned parallel with eachother to form the keyboard as is Well known in the art. A wooden key shank 11 is covered by plastic cap 13 on a front portion there- 4 of. The front portion of key shank 11 also includes a hole 15 in which a bushing 16 is disposed.

The key frame upon which the key rests includes a front rail 21 in which a metal key pin 23 has been driven. This pin acts as a guide for the front end of key shank 11 by cooperating with the bushing 16 as is known in the art. A felt washer 25 is disposed between the bushing 16 and the rail 21 to damp out noise.

The rear portion of key shank 11, that is, that endY of the shank opposite key cap 13, may be utilized in a well known manner to operate the piano hammer mechanism. The key is shown in solid lines in FIG.v 1 in normal position, and when pressure is applied to the top of the key cap, the rear end of the key shank 11 is raised to the position indicated by the phantom lines in FIG. 1 to operate the piano hammer mechanism. A felt cloth pad 27 is utilized at the rear end of the key shank 11 to damp out noise.

Key shank 12 is held in position with respect to a balance rail 31 and is rendered pivotal'with respect to the balance rail 3-1 by means of a balance pin 33. Balance pin 33 comprises an upper segment 35 and a lower segment 36. Segments 35 and 36 areelongated and cylindrical in cross section and are axially aligned. Segments 35 and 36 are joined by a hinged portion of I-s'haped cross section which is comprised of a flange 37 fixed on one end of segment 35 and a flange 38 fixed on one end of segment 36. Flanges 37 and 38 are elongated and extend transversely to their respective segments. A ilexi-l ble resilient web joins flanges 37 and 38 and forms a hinge to permit the balance pin 3-3 to flex. vA groove 41 is provided running `the length of balance rail 31. Groove 41 has a hole 43 in the bottom thereof and segment 36 of balance pin -33 is Ifixed in hole 43 with a push fit to be securely held therein. Flange 38 mates with groove 41 to holdthe pin 33 in proper alignment with respect to the balance rail 31 and the key 11. As shown in FIGS. 1 and `2, rotation of the pin 33 with respect to the balance rail 31 is prevented by the cooperation between iiange 38 land groove 41. The upper segment 35 of the pin, which is slightly longer than lower segment 36, fits loosely in a hole `45 in the key shank 11. A felt washer `47 is placed between the ange 37 and the lower edge of key shank `11 to damp out noise.

By providing an integral balance pin of iiexible plastic, production cost is greatly decreased as the pins may be molded and little or no machining is required to iinish them. The material cost -may be lower'and scrapped pieces are more readily re-used. The family of plastic materials found to be best suited for -the balanceA pin-'is that of the acetal resins. Such a plastic is available from the Dupont Corporation of Wilmington, Delaware, under the trademark Delrin. Polypropolene vplastic has Valso been found satisfactory. In addition to lower manufac-` turing and material costs, such balance pins avoid the danger of splitting the balance rail because, rather than driving such pins into the balance rail, they are inserted and gripped in a prebored hole. In addition, no bushing is required in the hole in the` key shank because the upper segment of the pin moves with the shank. The integral I-shaped cross sectional hinge portion joining the upper and lower segments of the pin provides strength and stability to the pin and enables alignment or orientation of the balance pin with respect to the balance rail for .proper motion of the key by locking in the groove in the balance rail.

It may therefore be seen that the invention provides an improved low cost keyboard assembly for musical instruments which dispenses with the need for balance bushings in the keys. The invention further provides a-low cost balance pin' facilitating the manufacture of keyboards.

I claim:

1. A balance pin of fiexible plastic material and uni# tary construction for use in a musical keyboard instrument, and comprising, first and second elongated segments, said first segment being adapted for insertion in a hole of the balance rail of the instrument and said second segment being adapted for insertion in a hole in a key of the instrument, said first segment terminating in an elongated flange portion extending transversely thereof, and a resilient iiexible web portion extending 'between said first and second segments to provide a hinge connection therebetween, said elongated fiange portion of said first segment serving to align said pin with respect to the balance rail and to prevent rotation of said pin with respect to the balance rail.

2. A balance pin for use in a ,musical keyboard instrument comprising rst and second axially aligned elongated cylindrical segments, said first segment being adapted for insertion in a hole of the balance rail of the instrument, said second segment being adapted for insertion in a hole in a key of the instrument, and an integral hinge portion of I-shaped cross section joining the adjacent ends of said first and second cylindrical segments, said hinge portion having rectangular flanges extending transversely of said segments and a resilient flexible web extending between said flanges, said flange of said hinge portion adjacent said first segment being adapted to cooperate with the balance rail to align said pin and prevent rotation of said pin with respect to the balance rail.

3. A balance pin of flexible plastic and unitary construction for use in a musical keyboard instrument, said balance pin comprising first and second axially aligned elongated cylindrical segments, said first segment being adapted for insertion in a hole of the balance rail of the instrument, and said second segment being adapted for insertion in` a hole in a key of the instrument,` and an integral hinged portion of I-shaped cross section and including first and second elongated flange portions disposed on the adjacent ends of said first and second cylindrical segments respectively, said hinge portion further including a resilient fiexible web extending between said flanges along the full length of said anges to provide a hinge f connection therebetween, said flange portion adjacent said first segment being adapted to cooperate with the balance rail to align said pin and prevent rotation thereof with respect to the balance rail.

4. In a keyboard for a musical instrument, the combination including, a balance rail, a groove in said balance rail, said balance rail having a hole therein opening in said groove, a key having a hole aligned with said hole in said balance rail, and a balance pin supporting said key on'said balancerail'and comprising a rst elongated cy lindrical segment disposed in said hole in said balance rail and a second elongated cylindrical segment axiallyl alignedwith said first segment and disposed in said hole in said key, said balance pin further comprising an integral hinge portion joining the adjacent ends of said first and second segments, said hinge portion having a flange extending transversely of said first segment and a resilient flexible web portion joining said segments, said fiange being disposed in said groove in said balance rail to-fhold said balance pin in given rotary alignment with respect to said balance rail.

5. In a keyboard for a musical instrument, the combination including an elongated balance rail, groove in said balance rail, said balance rail having a hole in said groove, a key having a hole aligned with said hole in said balance rail, and a balance pin of flexible plastic and of unitary construction, said balance pin joining said key to said balance rail and comprising a first elongated cylindrical segment disposed in said hole in said balance rail and a second elongated cylindrical segment axially aligned with said first segment and disposed in said hole in said key, said balance pin further comprising an integral hinge portion joining said first and second segments, said hinge portion being of VI-shaped cross section and having a first fiange on an end of said first segment and extending transversely thereof and a second flange disposed on the adjacent end of said second segment and extending transversely thereof, said first and second fianges being joined by a resilient 'exible web portion extending along the full length of said flanges. to provide a hinge connection therebetween, one of said flanges being disposed in said groove in said balance rail to hold said balance pin in a given alignment with respect to said balance rail and prevent rotation of said pin with respect to said balance rail.

References Cited by the Examiner UNITED STATES PATENTS 373,924 11/1887 Church 84-435 998,192 7/1911 Mayor 84-435 1,118,939 12/1914 Lawrence 84-435 1,148,085 7/1915 Goble 84-435 1,403,401 1/ 1922 George 84-435 2,470,148 5/ 1949 Demuth 84-423 FOREIGN PATENTS 6,656 8/1879 Germany.

324 1889 Great Britain.

References Cited by the Applicant UNITED STATES PATENTS 820,289 5/1906 Doyle.

LEO SMILOW, Primary Examiner.

C. M. OVERBEY, Assistant Examiner. 

1. A BALANCE PIN OF FLEXIBLE PLASTIC MATERIAL AND UNITARY CONSTRUCTION FOR USE IN A MUSICAL KEYBOARD INSTRUMENT, AND COMPRISING, FIRST AND SECOND ELONGATED SEGMENTS, SAID FIRST SEGMENT BEING ADAPTED FOR INSERTION IN A HOLE OF THE BALANCE RAIL OF THE INSTRUMENT AND SAID SECOND SEGMENT BEING ADAPTED FOR INSERTION IN A HOLE IN A KEY OF THE INSTRUMENT, SAID FIRST SEGMENT TERMINATING IN AN ELONGATED FLANGE PORTION EXTENDING TRANSVERSELY THEREOF, AND A RESILIENT FLEXIBLE WEB PORTION EXTENDING BETWEEN SAID FIRST AND SECOND SEGMENTS TO PROVIDE A HINGE CONNECTION THEREBETWEEN, SAID ELONGATED FLANGE PORTION OF SAID FIRST SEGMENT SERVING TO ALIGN SAID PIN WITH RESPECT TO THE BALANCE RAIL AND TO PREVENT ROTATION OF SAID PIN WITH RESPECT TO THE BALANCE RAIL. 